Apparatus for sharpening circular knives



Dec. 29, 1925- V. VAN DAMME APPARATUS FOR SHARPENING CIRCULAR KNIVES Filed Feb. 9,' 1921 lll-Ii,

Patented Dec. 29, 1925.

UNITE STATES Laatst PATENT orties.

VICTOR VAN DAMME, OF ANTWERP, BELGIUM, ASSIGNOR TO THE NEW ELSWICK TRADING COMPANY LIMITED, OF DEVENTER, NETHERLANDS, A COMPANY OF THE NETHERLANDS.

APPARATUS FOR SHARPENING CIRCULAR KNIVES.

Application filed February 9, 1921.

Serial No. 443,675.

(GRANTED UNDER THE PROVISIONS 0F THE ACT 0F MARCH 3, 1921, 41 STAT. L., 1313.)

To all whom t may concern.'

Be it known that I, VICTOR VAN DAMME, a subject of the King of Belgium, residing at Antwerp, in the Kingdom of Belgium, Quai Flamand, have invented certain new and useful Improvements in Apparatus for Sharpening Circular Knives (for which I have obtained a Pat-ent #260,010, in Belgium, filed Aug. 23, 1913) of which the following)- is a specification.

This invention comprises an improved apparatus for sharpening circular knives such as are employed for example in meat slicing machines andfor like purposes.

Machines for sharpening circular knives having two working grinding discs are well known in which machines one disc performs the actual sharpening action whilst the other disc grinds away the burr formed during the grinding.

In these known apparatus the grinding discs are pressed by spring pressure against the knife to be sharpened. These sharpening apparatus have the disadvantage that the spring is kept always under a certain tension or must always be adjusted to a given tension in order to enable the sharpening action to be effected. If in the course of time the spring slackens or loses its elasticity the circular knife is no longer sharpened with the necessary degree of finene'ss, while on the other hand if the spring is under too great pressure the knife is ground away too rapidly.

Now this invention has for its object to remove this disadvantage.

rEhe following are the characteristic features of the invention.

(l) The drive and rotary movementof the grind stone is operated and produced without the use of separate driving means and transmitting members, such for example as belt pulleys, gear wheels or lever transmissions, but merely by the friction which the rotating circular knife to be ground exerts on the grind stone.

(2) The grind stone is adjusted into the operative position merely by its weight and is held .in this operative position by the same during the operation of grinding or sharpening, and;

The removal of burr formed by the grinding is effected by means of a whetting steel, the rotary movement of which is produced merely by the friction which the rotary circular knife exerts on the steel, special means of driving being dispensed with.

For this object the shaft of the grind stone may be revolubly mounted in a cylinder. rlhe axis of rotation and the cylinder are permanently inclined. The cylinder is displaceable and adjustable at this inclination which is greater than the angle of friction. With this arrangement during the grindmg operation the grind stone presses lightly merely by its own weight against the edges of the knife to be sharpened so that the grind stone can follow exactly and easily the slightest movement of the rotating knife, whereby a very sharp cutting edge is obtained while a uniform sharpening of the knife is effected.

The invention will now be `described with reference to the example of construction shown in the accompanying drawings, in which Fig. 1 is a side view of the arrangement.

Fig. 2 a view of the grind stone rotatably mounted in the guide cylinder.

3 is a horizontal section on the lino I-I of Fig. 1.

Fig. l is a. side view of a guide piece in detail mounted on the machine frame and shows diagrammatically the method of attaching this guide piece to the frame of the sharpening machine.

Fig. 5 is a side view of the guide piece shown in Fig. 4 but viewed from the opposite side.

Figs. 6 and 7 are front and side views respectively of a second guide piece which is displaceably mounted in the first mentioned guide piece and on which the actual grind stone carrier is fixed.

Figs. 8 and 9 are front and side views respectively of the grind stone carrier.

The arrangement of the apparatus is as follows:

A guide piece a in which a guide piece c is vertically, adjustably, and displaceably mounted, is seated on the frame b of the grinding machine. The actual stone carrier Z is fixed on the displaceable guide piece 0, for example by means of a screw nut n.

This grind stone carrier l is provided With two inclined upwardly directed arms or supports p and g of different length, which arms carry rings i, s in which a cylinder e may be displaceably mounted. This cylinder c is fixed in position by means of set screws 7c in the ring 7".

The difference in the length of the arms r, s gives the angle of inclination of the grind stone, and this difference of heights is selected so that the angle of inclination of the cylinder e is greater than that of the angle of friction.

The grind stones are mounted on the shaft f which is carried in ball bearings in the cylinder e. On the shaft f the actual grind stone r/ and a Whetting steel 71. are

mounted, the latter sharing in the rotary movement of the grind stone.

The grind stone f/ rubs on the outside of the circular knife and produces the actual cutting edge, and the whetting steel 7i ren moves (after the grind stone has been drawn away from the knife), the burr formed on the inner sides of the knife by the grinding. z' is the knife edge.

This displacement of the grind stone carrier (l in a horizontal direction is effected by the bolts o and w which are adapted to be displaced in horizontal grooves m and y. The bolts o and fw are locked by means of nuts n and e.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim iszl. Tn a knife grinding machine, a shaft, means for mounting said shaft in an inclined position, said means being adapted to permit free longitudinal and rotary movement of said shaft, a. grinding Wheel mounted adjacent the lower end of said shaft adapted to contact With a rotating circular knife whereby the grinding pressure is produced solely by the Weight of the Wheel andxthe associated parts and the rotation of the grinding Wheel is effected by the friction between the knife and Wheel.

2. Tn a knife grinding machine, a shaft, means for mounting said shaft in an inclined position, said means being adapted to permit free longitudinal and rotary moveinout of said shaft, a grinding Wheel mounted adjacent the lower end of said shaft, adapted to Contact with a rotating circular -rnife whereby the grinding pressure is produced solely by the Weight of the Wheel and the associated parts and the rotation of the grinding Wheel is effected by the friction between the knife and Wheel and a Whetting Wheel on said shaft for removing the burr caused by the grinding Wheel, said Whetting Wheel being adapted to be pressed against said knife and rotated solely by the rotation of said knife.

Tn testimony whereof I afiiX my signature.

VICTOR VAN DAMME. 

